This application is the US National Stage filing of PCT Application Serial Number PCT/JP99/05721, which PCT application claims priority to Japanese Patent Application Serial Numbers 11-61915, 11-128939 and 11-165863.
The present invention relates to sewing machines that are capable of forming stitches or embroidery on a peripheral surface of a tubular that will be sewn (tubular objects), and in particular, a tubular article that has a small diameter.
Conventionally, if an embroidering operation or the like is performed on the periphery of a tubular object, such as a cap having a large diameter, a tubular frame having a large diameter is also used to support the tubular object. However, the tubular object may also have a small diameter, such as a cover for a golf club or a wrist band. If a sewing operation is performed on such a tubular object having a small diameter, the frame that supports the object also must have a small diameter. The frame is mounted on a drive ring that reciprocally moves in both linear and rotational directions, and the frame is operated to linearly move and to rotate around a cylinder bed by the actuation of the drive ring during the sewing operation. The cylinder bed includes a shuttle disposed therein, and a throat plate having a needle hole is secured to the upper surface of the cylinder bed by means of screws or the like in a position opposing the shuttle.
It is very difficult to position the aforementioned drive ring and the frame having a small diameter as near as possible to the outer peripheral surface of the cylinder bed and still support the drive ring, such that the drive ring can stably rotate. In addition, when such a small frame rotates together with the tubular object around the cylinder bed during the sewing operation, the tubular object (interlining) may be caught and block the edge of the throat plate or the boss portion of the needle hole that protrudes from the surface of the throat plate. As a result, it is difficult to suitably perform a sewing operation, such as an embroidery operation, on small tubular objects, such as golf club covers and wrist bands.
Further, in order to perform the sewing operation over a wide range in the circumferential direction of the tubular object, it is necessary to provide a frame having a wide sewing window; further, an interlining is required to support the tubular object, such that the tubular object does not sink into the sewing window. Because the interlining is intended to support the tubular object along the wide sewing window, a paper material or a non-woven fabric, which has a suitable thickness and rigidity, is used as the interlining.
In order to retain a tubular object and its interlining on the frame, the tubular object is placed on the frame together with the interlining, which is positioned inside of the tubular object, and the tubular object is retained to thereby retain the interlining. However, in operation, it is difficult to handle the tubular object together with the interlining, and it is difficult to stably retain the tubular object because the interlining may slip off the sewing window of the frame.
It is an object of the present invention to enable a drive ring to smoothly and stably rotate, while disposing the driver ring and a frame having a small diameter as near as possible to an outer peripheral surface of a cylinder bed.
It is another object of the present invention to prevent a tubular object from being caught by an edge of a throat plate or the like during rotation of the frame together with the tubular object around the cylinder bed, so as to enable an embroidery operation or similar operation to be performed over a wide range in the circumferential direction of the tubular object that has a small diameter.
It is a further object of the present invention to individually hold a tubular object and its interlining against the frame so as to facilitate the sewing operation and to also enable a frame having a small diameter and a wide sewing window to be stably held.
According to one aspect of the present invention, in a sewing machine, a cylindrical frame for holding tubular objects is mounted integrally on a cylindrical drive ring that is reciprocally driven in a rotational direction around a cylinder bed and that is linearly reciprocally driven along an axis of the cylinder bed. The cylindrical drive ring is rotatably supported by a support member that is arranged to contact the outer periphery of the drive ring at three or more positions.
By utilizing this construction, not only the drive ring, but also the frame that is mounted thereon, may have a small diameter, and the drive ring can be stably supported by the support member so that the drive ring will smoothly rotate. As a result, the frame can retain a tubular object having a small diameter, such as a golf club cover or a wrist band, and a sewing operation, such as an embroidery operation, can be suitably performed on the periphery of the tubular object.
According to another aspect of the present invention, the diameter of the drive ring is selected such that the inner periphery of the drive ring is disposed as near as possible to the outer peripheral surface of the cylinder bed.
Additional embodiments taught for stably rotating the drive ring. Thus, in another aspect of the present invention, the drive ring is rotatably supported by a support member against a plate that is linearly reciprocally moved along the axis of the cylinder bed. Further, the drive ring is constructed such that it is reciprocally moved in the rotational direction around the cylinder bed by means of a cable, which is wound about the drive ring. In addition, the support member comprises three or more rollers that are rotatably supported on the plate.
In another aspect of the present teachings, the cylinder bed includes a shuttle disposed therein, a needle hole provided in a position opposing the shuttle, and a support arranged to provide an internal support for the tubular object retained by the frame. The support includes a receiver portion that extends at least in the vicinity of the needle hole along an arc, which arc is substantially coaxial with the rotational axis of the frame.
Therefore, the tubular object can be supported in an arc shaped configuration by the receiver portion of the support at least in the vicinity of the needle hole, so that the tubular object may not be caught by cylinder, bed-side parts during rotation of the frame around the cylinder bed. As a result, tubular objects having small diameters also can be properly mounted and can be suitably sewn over a wide range in the circumferential direction.
In another aspect of the present invention, the support includes the receiver portion and a joint portion, and the support is integrated with the cylinder bed by means of the joint portion. Further, the arc-shape of the receiver portion includes a cylindrical shape about an axis that is coaxial with the rotational axis of the frame. In addition, the outer peripheries of both ends of the receiver portion are formed as tapered surfaces so as to provide a smooth guide for the tubular object.
In particular, by configuring the receiver portion to have a cylindrical configuration and by forming the outer peripheries of both ends of the receiver portion as tapered surfaces, it is almost impossible for the tubular object and its interlinings to be caught during the sewing operation.
In another aspect of the present invention, the frame includes a tubular receiver frame that can be positioned on the outer periphery of the tubular object, a sewing window opens within the receiver frame over a predetermined range, and the tubular object and its interlining can be individually retained in the area of the sewing window.
In particular, although a wide sewing window is needed for a small receiver frame if small tubular objects are to be processed, and if a sewing operation, such as an embroidering operation, is performed on the object over a wide range in the circumferential direction, it is possible for the interlining to be first retained in the area of the sewing window and the tubular object is thereafter retained. In this case, these operations can be easily performed and it is possible to stably retain the articles to be sewn.
In another aspect of the present invention, the sewing window opens on both the upper and lower sides of the receiver frame, and the sewing machine is constructed such that the tubular object and the interlining can be individually retained by each of the areas of the sewing window.
Therefore, the tubular object and the interlining can be sewn individually within the areas of the sewing windows without the need to reset the tubular object and the interlining on the frame; thus, operation efficiency can be improved.
In another aspect of the present invention, the frame includes a presser frame for holding a tubular object against the receiver frame and includes a presser frame for holding an interlining, thereby enabling the tubular object and the interlining to be individually retained as described above.
Additional embodiments relate to the presser frames. Thus, in another aspect of the present invention, one end of each of the presser frames is pivotally connected to the receiver frame. The sewing machine is constructed such that the presser frame for the interlining is laid over the presser frame for tubular objects. In addition, the presser frame for supporting the tubular objects includes a lock member that can engage the receiver frame. Therefore, both presser frames can be retained against the receiver frame by engaging the presser frame for supporting the tubular objects against the receiver frame by means of the lock member.
In another aspect of the present teachings, one of the presser frames can be set on the receiver frame with the interlining being retained therebetween. The other of the presser frames can be set on the former presser frame with the tubular object being retained therebetween.
In another aspect of the present teachings, the receiver frame includes a spring member for holding the interlining, and further the presser frame is wound around the receiver frame so as to be set on the receiver frame and to hold the tubular object. Further, the presser frame includes a flexible frame, which has a window, which is sized to correspond to the sewing window of the receiver frame, and connecting strips that are connected to both sides of the flexible frame. In addition, a slip prevention member is disposed around the sewing window of the receiver frame. A pressing member is disposed around the window of the flexible frame so as to correspond to the slip prevention member, which is disposed around the sewing window. Therefore, the construction for holding the tubular object and its interlining against the receiver frame can be simplified.
Additional features, aspects and advantages of the present invention will be become more fully apparent by reading the following description in conjunction with the drawings.